1. Field of the Invention
The present invention relates to a tool transfer device for machine tools designed to transfer a next-process tool that is taken out from a tool magazine, where a multiplicity of tools are accommodated and held, to a tool changing position by a transfer pot.
2. Discussion of the Related Art
In some machine tools equipped with a tool changer, in order to enable production of a variety of product types with continuous automatic operation, a rack type tool magazine for accommodating and holding therein a multiplicity of tools is disposed on one side of the machine body with the tools directed perpendicular to the axis of the spindle, while a tool transfer device is mounted for transferring a next-process tool from the tool magazine to a tool changing position where the tool is positioned parallel to the axis of the spindle.
One such a tool transfer device has generally been provided having the following structure. That is, a transfer pot that is driven by a horizontal moving unit and a vertical moving unit is disposed on the spindle side of the tool magazine. A next-process tool accommodated in the tool magazine is taken out and moved horizontally by the transfer pot, thereby it is transferred up to a stroke end position. At the stroke end position, the next-process tool is moved over by being pulled out from the transfer pot and inserted into a tilting standby pot. The tilting standby pot is tilted by a tilting device such as a cylinder mechanism so that the next-process tool is positioned to a tool changing position where the tool is parallel to the axis of the spindle. Then, the next-process tool in this tool changing position and a process-completed tool in the spindle are automatically exchanged by the tool changer.
However, in this conventional tool transfer device where the next-process tool is tilted to the tool changing position by the tilting device after being moved over from the transfer pot into the tilting standby pot, there are problems that a loss of tool transfer time is involved. Further the cost of the device increases due to the additional requirement for a driving source for the tilting operation.